The entire disclosure of Japanese Patent Application No. 2000-152437 filed on May 24, 2000 including specification, claims, drawings, and abstract is incorporated herein by reference in its entirety.
1. Field of the Invention
This invention relates to an inking device of a rotary press.
2. Description of the Related Art
Among rotary presses, there has been a four-color double-sided simultaneous offset printing press as shown, for example, in FIG. 5 (see Japanese Patent No. 2612594). According to this type of printing press, a blanketed impression cylinder 101 with a paper gripping device and a blanket cylinder 102 without a paper gripping device are supported in a nearly horizontal position in a printing unit 100, with the circumferential surfaces of the blanketed impression cylinder 101 and the blanket cylinder 102 being in contact with each other. Four plate cylinders 103 are arranged on the circumferential surface of the blanketed impression cylinder 101, and four plate cylinders 104 are similarly arranged on the circumferential surface of the blanket cylinder 102. Inking units 105, 106 are provided to be movable toward and away from the plate cylinders 103, 104, and can supply ink and water while contacting the plate cylinders 103, 104.
On the other hand, a delivery cylinder 108 of a delivery unit 107 is disposed below the blanketed impression cylinder 101, and a chain 109 is disposed leftward of the delivery cylinder 108 without crossing a space below a position of contact between the circumferential surfaces of the blanketed impression cylinder 101 and the blanket cylinder 102. Transfer cylinders 111 to 114 with paper gripping devices are provided for transferring a sheet from a register 110 to the blanketed impression cylinder 101. Similarly, a transfer cylinder 115 with a paper gripping device is provided for transferring a sheet from the blanketed impression cylinder 101 to the delivery cylinder 108. Numeral 116 denotes a feeder.
A sheet fed from the feeder 116 and positioned by the register 110 is transported along a route indicated by arrows in the drawing, namely, along the circumferential surfaces of the transfer cylinders 111 to 114, blanketed impression cylinder 101, transfer cylinder 115, and delivery cylinder 108 in this order. When the sheet passes through the point of contact between the blanketed impression cylinder 101 and the blanket cylinder 102 downwardly from above, both sides of the sheet are printed simultaneously.
In the inking units 105, 106, inking devices 105a to 105d, 106a to 106d for four colors are provided. These inking devices 105a to 105d, 106a to 106d each have an ink fountain roller rotating with a shaft thereof rotatably supported by right and left frames, and an ink fountain device has a triangular cross sectional shape formed by the circumferential surface of the ink fountain roller, dam plates at the ends of the ink fountain device, and ink blade sections. Ink stored in the ink fountain device flows out from a gap between the circumferential surface of the ink fountain roller and the front ends of the ink blade sections upon rotation of the ink fountain roller, and the ink adheres to the circumferential surface of the ink fountain roller. Near the ink fountain roller, an ink distribution roller parallel thereto is rotatably disposed. The ink, adhered to the circumferential surface of the ink fountain roller, is transferred to the ink distribution roller by an ink ductor roller which is supported by an arm and reciprocates between the ink fountain roller and the ink distribution roller upon swaying of the arm. Then, the ink is uniformly flattened in different directions while being transferred among many groups of ink rollers, whereafter the ink is supplied to a plate surface on the plate cylinder by ink form rollers.
In the so constituted inking devices 105a to 105d, 106a to 106d, the ink fountain device has conventionally been switchable between two positions, i.e., an ink fountain position during printing (fixed position), and an ink fountain position during cleaning, adjustment, or long-term machine shutdown (throw-off position). As a method of fixing the inking devices 105a to 105d, 106a to 106d at the fixed position, a bolt-nut fixing method manually conducted by an operator has been adopted.
With the conventional inking device, the ink fountain device can be switched only between two positions as stated above. Thus, in a four-color double-sided simultaneous offset printing press having the ink fountain devices arranged vertically in multiple stages, for example, when the unused ink fountain devices are switched to the throw-off position, a space in a vertical direction between the unused ink fountain devices and the ink fountain devices, in use, located below them becomes small. This has made it difficult to secure a vertical space for operating the ink fountain. In addition, the conventional ink fountain device is fixed by the bolt-nut fixing method relying on the operator""s manual work. Hence, a change in a clamping force occurs during fixing, thereby changing the amount of gap between the ink fountain roller and the ink blade sections and vary the amount of ink being fed. A clamping force control method using a torque wrench is also carried out. However, this method has involved the inconvenience of requiring a tool.
The present invention has been conceived in consideration of the above-mentioned problems with the earlier technology. It is an object of the present invention to provide an inking device of a rotary press which makes it easy to secure a vertical space for operating an ink fountain, and which can fix an ink fountain device with a constant clamping force without using a tool.
The present invention, which attains the above object, is an inking device of a rotary press, which comprises an ink fountain roller supported rotatably, and an ink fountain device movable toward and away from the ink fountain roller, wherein the ink fountain device is switchable among a fixed position close to the ink fountain roller, a throw-off position separated from the ink fountain roller, and an intermediate position provided between the fixed position and the throw-off position, and switching means is provided for switching the ink fountain device at any of the three positions. Thus, the inking device can easily secure a vertical space for operating an ink fountain, and can fix the ink fountain device with a constant clamping force without using a tool.
The ink fountain device may have a first spring member for pressing the ink fountain device when the ink fountain device is located at the fixed position to prevent backlash of the ink fountain device by the first spring member.
The switching means may comprise an eccentric pin rotatably supported by at least one of the frames, a locking handle fixedly provided on the eccentric pin, and a hook pivotably fitted onto an eccentric shaft portion of the eccentric pin, and releasably supported on an engagement pin provided on the ink fountain device. The locking handle can be held at a first position, at which the ink fountain device is held at the fixed position, with the hook being engaged with the engagement pin, and a second position, at which the ink fountain device is held at the intermediate position, with the hook being engaged with the engagement pin. The locking handle can also move to a third position at which engagement between the hook and the engagement pin can be released.
Holding means for holding the locking handle at each of the first position, the second position, and the third position may be provided. The holding means may comprise grooves, an engagement member for engaging the groove, and a second spring member for urging the engagement member in a direction in which the engagement member engages the groove.
Release means may be provided for releasing the hook from the engagement pin when the locking handle is located at the third position, and the hook may be disengaged from the engagement pin by moving the ink fountain device upward. The release means may have a third spring member for urging the hook in a direction in which engagement of the hook with the engagement pin is released, when the locking handle is located at the third position, and for releasing an urging force on the hook when the locking handle is located at the first position or the second position.
The engagement pin may be engaged with the hook by upwardly moving the ink fountain device located at the throw-off position when the locking handle is located at the second position.
The hook may have, at a front end thereof, an inclined surface raised by the engagement pin. The hook raised by the engagement pin may engage the engagement pin by the own weight of the hook.